Strop was placed on the 10-day injured list Tuesday due to left neck tightness, retroactive to Saturday Gordon Wittenmyer of the Chicago Sun-Times reports.
This move by the Cubs was expected, though it remains to be seen how long Strop will need to return to health. He'll be eligible to be reinstated beginning Aug. 6. Duane Underwood was recalled from Triple-A Iowa in a corresponding move.